With the gradual population of wearable application equipments, such as smart glasses, smart phone, et cetera, the demands to flexible display in the display industry have constantly increased.
An Organic Light Emitting Diodes Display (OLED) possesses properties of self-illumination, no required back light, being ultra thin, wide view angle, fast response and etc., and accordingly has the nature advantage of flexible display. However, the OLED industry remains the extremely high bar of technology. The difficulty of the manufacture process is high. The yield is low and the cost is high. These drawbacks get in way of wide applications of the OLED.
The Liquid Crystal Display (LCD) is the most widely used display product in the present market. The production technology is quite mature. The yield of the production is high. The cost is relatively low and the acceptance is high in the market.
Normally, the liquid crystal display comprises a shell, a liquid crystal display panel located in the shell and a backlight module located in the shell. The liquid crystal panel comprises a Color Filter (CF), a Thin Film Transistor Array Substrate (TFT Array Substrate) and a Liquid Crystal Layer filled between the two substrates. Transparent electrodes are formed at the inner side of the CF substrate and the TFT substrate. The liquid crystal display performs control to the orientation of the liquid crystal molecules in the liquid crystal layer with an electric field to change the polarization state of the light. The objective of display is achieved with the polarizer to realize the transmission and the obstruction of the optical path.
FIG. 1 is a structural diagram of a liquid crystal panel according to prior art in plane state. The liquid crystal material in the liquid crystal layer 300 is fluid which is flowable. The TFT substrate 100 and the CF substrate 200 are supported by the Photo Spacers (PS) 400 between the two substrates to maintain the Cell Gap and the Cell Gap evenness of the liquid crystal layer 300. In general conditions, the liquid crystal panel shown in FIG. 1 can satisfy the display evenness demands when the present liquid crystal panel in a plane state. The Cell Gap of the liquid crystal layer 300 is kept around the design value, and the Cell Gap is more even. However, after the liquid crystal panel previously in the plane state is bent, as shown in FIG. 2, the liquid crystal panel in a curved state suffers different stresses at various positions. The stress is larger where the curvature is larger. Consequently, the heights of the Photo Spacers 400 at various positions between the TFT substrate 100 and the CF substrate 200 are different. Meanwhile, the liquid crystal material in the liquid crystal layer 300 is pressed and flowing. Ultimately, it results in the uneven Cell Gap at various position of the liquid crystal layer 300.
The common liquid crystal panels in the main market can be categorized in three types, which respectively are Twisted Nematic/Super Twisted Nematic (TN/STN) types, In-Plane Switch (IPS) type and Vertical Alignment (VA) type. Although the principles of liquid crystal display adjustment are different, the basic structures of these three type liquid crystal panels are relatively similar. The display property and the Cell Gap of the liquid crystal layer are closely related. Whether the Cell Gap of the liquid crystal layer is even has the direct influence on the display effect. Changing the Cell Gap of the liquid crystal layer will affect the display brightness, contrast, response speed, etc. of the liquid crystal panel. Therefore, improvement is necessary to the traditional liquid crystal panel to solve the issue of uneven Cell Gap caused by the bent liquid crystal layer for allowing the liquid crystal panel adaptable for flexible display.